The field of the invention comprises support assemblies for suspending pipes and conduit from structural members, ceilings, and walls.
There are known in the prior art various forms of pipe hangers for supporting pipes, conduit, ventilation ducts, and the like within structures. Virtually all habitable structures require various combinations of plumbing pipes, ventilation ducts, electrical conduit, gas pipes, and the like to provide the necessary utility services. These pipes, conduit, and ducts, hereinafter termed pipes, are generally supported by pipe hangers that suspend the pipes from structural members within the building.
Pipe hangers generally comprise a plurality of suspension units that are spaced longitudinally along the pipe run, so that each suspension unit supports a small portion of the pipe and its contents. Prior art pipe hangers usually include a bracket to secure the hanger to a structural member, a strap, rod, bar, or the like extending downwardly from the bracket, and a pipe engaging clamp or strap secured to the depending member. Many combinations of these components are known in the prior art.
It may be appreciated that some pipe runs, such as waste pipes, are intentionally inclined, and the pipe hangers must be adjustable so that the spacing of the pipe from a supporting structural member differs smoothly and uniformly. Likewise, the structural members may be inclined while the pipe run is preferably horizontal. Thus, an important characteristic of pipe hangers is that they be adjustable in length to suit the situation in which the pipe is placed. In the prior art, there are known many arrangements for achieving adjustable spacing from the supporting structural member. For example, the bracket and/or strap and/or pipe clamp may be joined by threaded means, thereby providing infinite adjustment capability through a small range of vertical adjustability. Likewise, the depending strap may be provided with vertically spaced holes having a fixed spacing, and the pipe clamp may be secured by bolts or other fasteners in one of the preformed holes to approximate the desired vertical spacing. These devices are not infinitely adjustable, but they have a wider range of adjustability. Alternatively, the strap may be custom-formed on-site to provide the exact spaced desired.
A common problem found in prior art adjustable pipe hangers is that each installation required a great amount of manual labor to create the proper vertical spacing. For example, a typical pipe run may drop 1/4 inch per 4 feet, requiring that each hanger be slightly different from adjacent hangers. In addition, pipe runs must change direction to make required connections and avoid obstructions, and many prior art hanger assemblies are not easily adapted to angle changes. Moreover, this labor usually involves overhead work which is difficult and tiresome, especially when complicated by angled couplings and drop runs. These factors combine to cause a high labor rate for pipe hanger installations, in addition to the cost of the pipe hanger devices and materials.